diff --git a/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc b/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc
index 9431ba5fe1..d64cb7edbd 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc
@@ -52,24 +52,6 @@ struct CoreTextFontEngineData {
 /* https://developer.apple.com/documentation/coretext/1508745-ctfontcreatewithgraphicsfont */
 #define HB_CORETEXT_DEFAULT_FONT_SIZE 12.f
 
-static CGFloat
-coretext_font_size_from_ptem (float ptem)
-{
-  /* CoreText points are CSS pixels (96 per inch),
-   * NOT typographic points (72 per inch).
-   *
-   * https://developer.apple.com/library/content/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Explained/Explained.html
-   */
-  ptem *= 96.f / 72.f;
-  return ptem <= 0.f ? HB_CORETEXT_DEFAULT_FONT_SIZE : ptem;
-}
-static float
-coretext_font_size_to_ptem (CGFloat size)
-{
-  size *= 72.f / 96.f;
-  return size <= 0.f ? 0 : size;
-}
-
 static void
 release_table_data (void *user_data)
 {
@@ -104,7 +86,7 @@ _hb_cg_font_release (void *data)
 
 HB_SHAPER_DATA_ENSURE_DEFINE(coretext, face)
 HB_SHAPER_DATA_ENSURE_DEFINE_WITH_CONDITION(coretext, font,
-	fabs (CTFontGetSize((CTFontRef) data) - coretext_font_size_from_ptem (font->ptem)) <= .5
+	fabs (CTFontGetSize ((CTFontRef) data) - font->ptem) <= .5
 )
 
 static CTFontDescriptorRef
@@ -308,7 +290,8 @@ _hb_coretext_shaper_font_data_create (hb_font_t *font)
   if (unlikely (!hb_coretext_shaper_face_data_ensure (face))) return nullptr;
   CGFontRef cg_font = (CGFontRef) HB_SHAPER_DATA_GET (face);
 
-  CTFontRef ct_font = create_ct_font (cg_font, coretext_font_size_from_ptem (font->ptem));
+  CGFloat font_size = font->ptem <= 0.f ? HB_CORETEXT_DEFAULT_FONT_SIZE : font->ptem;
+  CTFontRef ct_font = create_ct_font (cg_font, font_size);
 
   if (unlikely (!ct_font))
   {
@@ -340,7 +323,7 @@ hb_coretext_font_create (CTFontRef ct_font)
   if (unlikely (hb_object_is_inert (font)))
     return font;
 
-  hb_font_set_ptem (font, coretext_font_size_to_ptem (CTFontGetSize(ct_font)));
+  hb_font_set_ptem (font, CTFontGetSize (ct_font));
 
   /* Let there be dragons here... */
   HB_SHAPER_DATA_GET (font) = (hb_coretext_shaper_font_data_t *) CFRetain (ct_font);